This disclosure relates generally to power consumption of electronic devices, and in particular, but not exclusively, relates to a method of determining the power consumption of a computer system.
Data centers are facilities designed to house large amounts of electronic equipmentxe2x80x94including devices such as computers, servers and routersxe2x80x94in a central location. Data centers are vital nodes in information superhighway. Data centers are designed to not only provide all the servers, storage systems and networking infrastructure required to support incoming data requests, but to also provide services such as: authentication, security, and RAS (reliability availability serviceability) management. Most often, data centers are large rooms that are closed off and heavily air-conditioned to maintain a suitable operating temperature for the equipment housed there. The rooms typically have racks where the data communication and processing equipment is installed. While there are many benefits to having all the equipment in one placexe2x80x94such as easier access and maintenancexe2x80x94data centers are costly to build and operate. Because of the high cost involved, space in a data center is at a premium, and data center facility managers try to squeeze as much equipment as possible into every data center. To do so, however, data center managers must have an accurate way of assessing the power consumption and cooling requirement of each component housed in the data center. For a data center, power and cooling are closely related, since a large portion of the electrical power consumed by a device usually ends up converted into thermal energy.
A power specification for a computer system, PMAX, usually defines maximum power capability of the power supply in the system. In the process of determining a value of PMAX, system designers usually consider the worst-case configuration of a system. Thus, PMAX for a system represents power consumption when the system is fully populated with hardware. The determination of PMAX also assumes that the system is configured with the most power hungry components capable of being used in that configuration, and that the system is running software that causes it to consume maximum power. For example, a server system may be designed to support four processors that may run at between 1.5 GHz and 2.2 GHz, 12 slots of memory, 8 slots for input/output (I/O) adapters and 5 bays for hard drives. The PMAX for such a system assumes the system is populated with all four 2.2 GHz (max power) processors, all twelve memory slots, all eight I/O slots populated with power hungry I/O adapters, and the system is using five hard drives.
The present methods for determining PMAX suffer from various disadvantages. First, most systems are populated with less hardware components than their capacity. Second, in the vast majority of cases not all the components used are the most power hungry. For example, many systems may be using processors slower than 2.2 GHz. Slower processors usually consume less power. On average, most of the systems could be consuming power far lower than PMAX.
Data center facility managers mistakenly interpret PMAX to be the actual power consumption of the system, rather than the maximum power capability of the power supply. As a result, data center managers currently use PMAX as a guideline to decide the amount of power and cooling they should provide for each rack, and for the data center as a whole. For systems that consume less power that PMAX, power delivery and cooling solution based upon PMAX may be over-designed and more expensive than necessary. Moreover, the philosophy of using PMAX generates demand on infrastructure, much higher than what would be actually needed. Data centers that use thousands of such systems, this could result in much large demand and expense on infrastructure.